InfoPath Dev

I created a form where the user does a saveas when a new job comes around to use the form on. However, changes were needed and I made those changes and published the changed form. However, there are forms now that will not open. I get the following message:

 This form was created with a new version of the form template. InfoPath cannot find the new version. Do you want to open the older version?

Then when I hit Yes, I get the following message: 

Element '{http://schemas.microsoft.com/office/infopath/2003/myXSD/2009-09-24T20:24:07}contractorCompany' is unexpected according to content model of parent element '{http://schemas.microsoft.com/office/infopath/2003/myXSD/2009-09-24T20:24:07}myFields'.

 What I believe is the "newer version" is what was published to the network for everyone to saveas to their computers. Is there any way to fix this so that these older forms can be viewed?

If changes are needed on a form that has already been used, what good is it to make the changes if the previous forms can never be opened?

It sounds like the problem is that you're having everyone save the XSN to their local drives and use them from there.  InfoPath forms are intended to be published to a single location and then used from there.  If you don't do that you're going to run into problems like this.

It is required that was as they end up using it when they are away from the office and not connected to the network on the internet.

In that case I think you need to look into using a URN-based solution, either by publishing the form as an installable (MSI) template, or publishing it to e-mail.

Is either option available in InfoPath 2003? If so, how do I go about doing them.